Among various display devices, liquid crystal display devices have such advantages as thinness, light weight, and low power consumption. For this reason, in recent years, liquid crystal display devices have been widely used instead of CRTs (cathode-ray tubes) in various fields of TVs (televisions), monitors, mobile devices such as cellular phones, etc.
A liquid crystal display device has its display system determined according to the way in which the liquid crystals are aligned within the liquid crystal cell. A liquid crystal display device of a conventionally known display system is an MVA mode liquid crystal display device. The MVA mode is a system under which a vertical electric field is applied by providing the electrodes of the active-matrix substrate with slits and providing the counter electrodes of the counter substrate with liquid crystal alignment controlling projections (ribs) so that the liquid crystals are aligned along multiple directions while controlling the alignment directions by using the ribs and the slits.
An MVA mode liquid crystal display device achieves a wide viewing angle by tilting the liquid crystal molecules along multiple directions when a voltage is applied. Further, since the MVA mode is a vertical alignment mode, the MVA mode can give higher contrast than a horizontal alignment mode such as an IPS (in-plain switching) mode. However, the MVA mode undesirably requires complex manufacturing steps.
In order to solve the processing problems with the MVA mode, a display system has been proposed (e.g., see Patent Literature 1) under which an electric field parallel to the substrate surfaces (so-called transverse electric field) is applied by using comb electrodes in a vertical alignment liquid crystal cell whose liquid crystal molecules are aligned along a direction perpendicular to the substrates when no voltage is applied.
The display system of Patent Literature 1 controls the direction of alignment of the liquid crystal molecules by driving with a transverse electric field while keeping the high-contrast characteristic based on vertical alignment. Unlike the MVA mode, the display system of Patent Literature 1 does not require control of alignment with use of projections, and as such, is simple in pixel configuration and has an excellent viewing angle characteristic.